Drain and Fill Brake Fluid Reservoir, Fruitless or Genius? LC100

[41togo]

Every bleed screw on my Tundra is seized, I’m afraid I’ll snap one off and be forced into an entire brake system refurb which I don’t have the time for now. I’m going to suck out the reservoir and refill a few times, it’s better than nothing.

Smart move! So my shop broken several rear sway bar bolts, advised me to bring her back after I get several new links as needing to be cut off. Also they are afraid to break the fuel tank straps bolts. I spray PB blasts and Kroil on the bolts for several months now. Last week I gave it a try and the bolts came off easily. I think I’ll need to soak the bleed screws too, once I bleed them this time I’ll get new rubber caps and spray some WD40 in it. I am hoping once I do a complete flash the next several years will be just suck out and refill the reservoir annually.

 

[OEMGUY0720]

Every bleed screw on my Tundra is seized, I’m afraid I’ll snap one off and be forced into an entire brake system refurb which I don’t have the time for now. I’m going to suck out the reservoir and refill a few times, it’s better than nothing.

The stem/threaded length of the bleed valve is not that short, unless the corrosion is that bad but the component itself is stout for its size. I’ve never snapped one before but I did unintentionally rounded a few because of how bad the corrosion and how the previous person strong handed it that it was already close to round and stuck.

The corrosion/rust on the brake hard lines is primarily from the chemistry composition of fluid. The lower DOT rating it has (glycol-based) the more susceptible it is to moisture hence oxidation = corrosion = rust. The higher the dot rating, the lower the chance for it to absorb moisture or even repel it (DOT5 silicone-based).

 

[GTV]

Smart move! So my shop broken several rear sway bar bolts, advised me to bring her back after I get several new links as needing to be cut off. Also they are afraid to break the fuel tank straps bolts. I spray PB blasts and Kroil on the bolts for several months now. Last week I gave it a try and the bolts came off easily. I think I’ll need to soak the bleed screws too, once I bleed them this time I’ll get new rubber caps and spray some WD40 in it. I am hoping once I do a complete flash the next several years will be just suck out and refill the reservoir annually.

The stem/threaded length of the bleed valve is not that short, unless the corrosion is that bad but the component itself is stout for its size. I’ve never snapped one before but I did unintentionally rounded a few because of how bad the corrosion and how the previous person strong handed it that it was already close to round and stuck.
View attachment 4006636
The corrosion/rust on the brake hard lines is primarily from the chemistry composition of fluid. The lower DOT rating it has (glycol-based) the more susceptible it is to moisture hence oxidation = corrosion = rust. The higher the dot rating, the lower the chance for it to absorb moisture or even repel it (DOT5 silicone-based).

I’ve given the screws many dousings of Kroil and liberal applications of heat, no dice, they ain’t budging. I can’t take the risk so a lazy man’s fluid exchange it is.

 

[baltistyle]

I’ve given the screws many dousings of Kroil and liberal applications of heat, no dice, they ain’t budging. I can’t take the risk so a lazy man’s fluid exchange it is.

Did you try a clean six sided deep impact socket on a long handled ratchet? Dont use a twelve point or open end or flare except to adjust once it's not seized anymore. You may also find the bleeder is blocked from debris and you can either remove and clean it or replace. I just did a flush today and this was what got my old stuck rear bleeders out. No penetrant but its zero rust rig.

 

[flintstone1]

Only one good way to clear/clean out the reservoir tank; With IG key ON, hold down brake pedal, open a rear caliper bleeder.

View attachment 3404255

Once reservoir very near the bottom. Close bleeder, turn off IG key then pump brake pedal 40 times (empties accumulator).
Accumulator dumps fluid back into to reservoir as you pump brake pedal with IG key off, to about level seen below.
Now add new Toyota brake fluid, doubling the amount currently in reservoir. (50/50 mix of old and new)
Now again clear/empty reservoir though rear bleeder. Repeat this 5 times.

After above flush, keep reservoir above low line at all times.
Now move to other rear, for a short flush of its line/caliper.
View attachment 3404256

Now move to FL, pump pedal 20 times IG key on. IG key now stay on until done.
Hold down pedal and open FL bleeder. Close bleeder and then pump pedal 5 times. Repeat 10 times. Only needing to pump pedal 5 times between each bleed., after the first 20 pump.
Never release brake pedal until bleeder closed, or air is suck in to caliper.

Now move to FR (front right). Bleed it, a minimum of 7 times.

Torque bleeders to 9 to 11ft-lbf. Blow out bleeder with brake clean (straw) than add WD-40 (w/straw) and cap them.

I use a minimum of 5 Toyota bottles, maximum 7 bottles. How many bottles depends on how much used to flush accumulator, the more the better. Also if caliper piston clasped, to get max out of calipers.

Once reservoir very near the bottom. Close bleeder, turn off IG key then pump brake pedal 40 times (empties accumulator).
Accumulator dumps fluid back into to reservoir as you pump brake pedal with IG key off, to about level seen below.
Now add new Toyota brake fluid, doubling the amount currently in reservoir. (50/50 mix of old and new)
Now again clear/empty reservoir though rear bleeder. Repeat this 5 times.

Probably a stupid question, when you repeat this 5 times do you pump the pedal 40 times each time you repeat the procedure or was it just the once? Cheers

 

[2001LC]

40 pumps, at start of each (repeat) of the 5 accumulator flushes.

 

[2001LC]

What are the final cut open reservoir pics showing?

Sorry for very delayed response. I missed your question. BTW: Much of what I talk about in this threads and more. Is in my Brakes Overdue Write Up

The picture show front cambers, with screen at bottom of LH camber. Notice on screen in LH side (your left as you face picture). The screen has black gunk (sludge) covering upper portion of screen. Unfortunately, I had lightly cleaned the cambers, before taking the pictures. Had I not cleaned. You'd see all screens had, black gunk covering them.

Same camber. Where black gunk is very clearly seen. This black gunk covered all screens.

Black brake fluid, heavily stained reservoir. You can bet, all the screens looks similar. Including those in ABS unit (black box on side of master)

Fluid allowed to get in such poor condition. Is damaging to seals and more. Most notably, a non replaceable seals, in front end master. When these seal damaged or just weakened. If we then, do anything, to improve pressure. By replacing, recondition or rebuilding. Any part of booster side of brake master ASSY. This seal, very often, fails to hold full pressure.

When this seals, fails to hold pressure. We then get squeal sound (dying Seagal), with bubble seen coming up front of reservoir. As booster system pressurizes. This is fluid passing the seal under high pressure. In the early stages of failure. Perhaps only heard & seen, on cold morning when first charging accumulator (IG key on). In time with use, squeal becomes more frequent. Result if excessive long booster motor run time, as it works to replace lost pressure. Which greatly reduce life of booster motor. As the motor, is designed to run for only short duration. Typically runs 3 to 5 seconds, expect when accumulator has be fully evacuated.

I've found this sludge, inside master. Most notably, inside ABS unit screens. This can cause ABS issues. One being. Activation of ABS, where say one of more valve is stuck. This can apply lite to full braking, to one or more calipers. Locking up that brake.
Here's screen on one ABS unit that lock up one rear caliper, on first press of brake pedal.

Clogged screen inside ABS unit.

Screen cleaned for comparison

 

[2001LC]

Bleeder's rubber cap. Caliper, insurance for pennies!

Bleeders frozen in, are a problem created by rust within bleeders port. I only see these rusted/frozen in bleeders, when bleeder caps not kept in place. Most notable, the rear bleeders. The rear bleeder are the worst. They sit a slight angle upward. So brake fluid/water doesn't just flow out, it sit in them. Getting down into inner chamber.

Sometime, out of fear of breaking a bleeder. I've heated and soak with penetrating oil, repeatedly over time. Most times these days, I just go for it and break the bleeders loose. I've learned over many brake jobs. The caliper bleeder are very strong. Perhaps, if so rust the metal has weaken, they'd break. But, I've not had one break! Knock on wood.

I use a 3/8" drive ~10" length breaker bar. With a deep, 6 point, 10mm socket. To break free these bleeders. Like I said. I've not broken a caliper bleeder to date. Which I've had many badly frozen in, where no heat or P-oil used.

I have had to, replace calipers, due to rust damaging the bleeders female seat area in caliper. What happens, is water/minerals enter the bleeders port, getting down into chamber around it in the caliper, just before/above seat (female). This chamber rust as does the bleeder. In time, this rust may, works it's way into calipers female bleeder seat. Then even a new bleeder, can't get a good seal. Due to rust pitted seat.

Bottom line, I don't fear breaking bleeder much anymore. Since, what I've found. If bleeder so frozen a bit of extra breaker bar force doesn't break free. Seat will be bad anyway. But, these seat don't get damaged often.

Blow out all bleeders & cap.

1. I use shop air, to blow residual brake fluid out after I've bleed. I cover with a rag and wear a mask. To avoid breathing vapors. I'd use, can air (key board compressed air), if I didn't have shop air.
2. Then I stick the straw of a can brake/parts clean, into bleeder port. Blow out with cleaner.
3. Blow out brake cleaner, with shop air.
4. Blow out with can of WD-40, using it straw. leaving DW40 in bleeder. Since it is water displacement agent.
5. Cap bleeder, with new rubber boot.

Female bleeder seat in caliper. This one looks usable

This one is questionable. New bleeder will not likely seal. Due to rust that worked it way down into seat within caliper. New caliper is cure, if leaks/weeps

 

[Jack90210]

I do a brake flush (a quart through the whole system) once a year while I am rotating tires. With a venturi-vac bleeder it adds maybe 15-20 minutes to the tire rotation job, plus I get to inspect the brakes.